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iterator_to_array

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

iterator_to_arrayCopy the iterator into an array

Beschreibung

iterator_to_array(Traversable $iterator, bool $preserve_keys = true): array

Copy the elements of an iterator into an array.

Parameter-Liste

iterator

The iterator being copied.

preserve_keys

Whether to use the iterator element keys as index.

If a key is an array or object, a warning will be generated. null keys will be converted to an empty string, float keys will be truncated to their int counterpart, resource keys will generate a warning and be converted to their resource ID, and bool keys will be converted to integers.

Hinweis:

If this parameter is not set or set to true, duplicate keys will be overwritten. The last value with a given key will be in the returned array. Set this parameter to false to get all the values in any case.

R├╝ckgabewerte

An array containing the elements of the iterator.

Beispiele

Beispiel #1 iterator_to_array() example

<?php
$iterator 
= new ArrayIterator(array('recipe'=>'pancakes''egg''milk''flour'));
var_dump(iterator_to_array($iteratortrue));
var_dump(iterator_to_array($iteratorfalse));
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

array(4) {
  ["recipe"]=>
  string(8) "pancakes"
  [0]=>
  string(3) "egg"
  [1]=>
  string(4) "milk"
  [2]=>
  string(5) "flour"
}
array(4) {
  [0]=>
  string(8) "pancakes"
  [1]=>
  string(3) "egg"
  [2]=>
  string(4) "milk"
  [3]=>
  string(5) "flour"
}

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User Contributed Notes 6 notes

up
4
jerome at yazo dot net
13 years ago
Using the boolean param :

<?php

$first
= new ArrayIterator( array('k1' => 'a' , 'k2' => 'b''k3' => 'c''k4' => 'd') );
$second = new ArrayIterator( array( 'k1' => 'X', 'k2' => 'Y', 'Z' ) );

$combinedIterator= new AppendIterator();
$combinedIterator->append( $first );
$combinedIterator->append( $second );

var_dump( iterator_to_array($combinedIterator, false) );

?>

will output :

array(7) (
  [0]=>
  string(1) "a"
  [1]=>
  string(1) "b"
  [2]=>
  string(1) "c"
  [3]=>
  string(1) "d"
  [4]=>
  string(1) "X"
  [5]=>
  string(1) "Y"
  [6]=>
  string(1) "Z"
)

<?php

var_dump
( iterator_to_array($combinedIterator, true) );

?>

will output (since keys would merge) :

array(5) (
  ["k1"]=>
  string(1) "X"
  ["k2"]=>
  string(1) "Y"
  ["k3"]=>
  string(1) "c"
  ["k4"]=>
  string(1) "d"
  [0]=>
  string(1) "Z"
)
up
3
joksnet at gmail dot com
7 years ago
To generate an deep array from nested iterators:

<?php
function iterator_to_array_deep(\Traversable $iterator, $use_keys = true) {
   
$array = array();
    foreach (
$iterator as $key => $value) {
        if (
$value instanceof \Iterator) {
           
$value = iterator_to_array_deep($value, $use_keys);
        }
        if (
$use_keys) {
           
$array[$key] = $value;
        } else {
           
$array[] = $value;
        }
    }
    return
$array;
}
?>

I use it to test an iterator: https://gist.github.com/jm42/cb328106f393eeb28751
up
2
Harry Willis
6 years ago
When using iterator_to_array() on an SplObjectStorage object, it's advisable to set $use_keys to false.

The resulting array is identical, since the iterator keys produced by SplObjectStorage::key() are always integers from 0 to (COUNT-1). Passing $use_keys=false cuts out the unnecessary calls to SplObjectStorage::key(), giving a slight performance advantage.
up
1
wizzard351 at yahoo dot com
1 month ago
One important thing to remember is that in iterator can be infinite. Not all iterators necessarily end. If iterator_to_array is used on such an iterator, it will exhaust the available memory, and throw a fatal error.

For example, consider the following code:

<?php

function fibonacci(): Generator
{
    yield
$a = 1;
    yield
$b = 2;

   
start:
    yield
$c = $a + $b;
   
$a = $b;
   
$b = $c;
    goto
start;
}

$fibonacciSequence = fibonacci();
iterator_to_array($fibonacciSequence);

?>

Since <?php fibonacci(); ?> generates an infinite fibonacci sequence, which is valid, since it is actually an infinite sequence, then attempting to convert it to an array will fail.
up
-2
enelar at develop-project dot ru
5 years ago
Generator approach

function scandir_deep($dir)
{
  foreach (scandir($dir) as $key => $value)
    if (in_array($value, [".",".."]))
      continue;
    else if (is_dir($dir . DIRECTORY_SEPARATOR . $value))
      yield $value => scandir_deep($dir . DIRECTORY_SEPARATOR . $value);
    else
      yield $value;
}
up
-4
chad 0x40 herballure 0x2e com
14 years ago
The use_keys parameter was added in one of the 5.2.x releases; it defaults to TRUE. This matches the behavior in PHP 5.1.6, which lacks this parameter.
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